Auto radial profile dresser



Feb. 26, 1957 H. E. BALSIGER 2,782,778

Y AUTO RADIAL PROFILE DRESSER ,Eiled June 10, 1954 5 Sheets-Sheet l I I INVENTOR LSIGER Feb. 26, 1957 H. E. BALSlGER 2,782,778

AUTO RADIAL PROFILE DRESSER Filed June 10, 1954 5 Sheets-Sheet 2 INVENTOR $4904.19 E. BALsIGER ATTORNEY Feb. 26, 1957 'H. E. BALSIGER 2,732,778

AUTO RADIAL PROFILE DRESSER Filed June 10, 1954 s Shets-Shet 3 INVENTOR f/HROLD E. EHLSIGER ATTORNEY United States Patent AUTO RADIAL PROFILE DRESSER Harold E. Balsiger, Waynesboro, Pa., assignor to Landis Tool Company, Waynesboro, Pa.

A toplication June 10, 1954, Serial No. 435,849 4 Claims. (Cl. 125-11) This invention relates to grinding wheel trueing devices particularly of the type generally known as a radial profile trueing device.

A radial profile trueing device is one in which the trueing tool rotates about a fixed center. However, it is guided by a template or profile so that the path which it follows is not a true circle. Ordinarily, dressers of this type are arranged to dress the wheel approximately at the point of contact between the wheel and the work piece. In this instance, the space available is so limited that the trueing tool is in the path of other parts during the grinding operation. This problem has been solved by making the diamond holder shorter so that it would engage the wheel at a point substantially above the point of contact between wheel and work. At the same time it is mounted at an angle so" that the axis about which the trueing tool moves will be substantially tangent to the grinding wheel at the point of engagement by the diamond.

It is an object of this invention to provide a trueing device for irregular curved shapes which is operable in a limited space.

Another object is to provide a simplified profile mechamsm.

Another object is to provide means for rotating the trueing tool so that the load on the shaft is uniform in all directions.

In the drawings,

Figure 1 is an end elevation of the trueing device partly in section.

Figure 2 is an enlarged end elevation partly in section showing the profile mechanism.

Figure 3 is a front sectional elevation showing the means for supporting and rotating the shaft on which the trueing tool is mounted.

Figure 4 is a sectional elevation of the feeding and rotating mechanisms and the hydraulic and electrical circuit for operating them.

In the drawings, numeral indicates the wheel base of a grinding machine and 11 a grinding wheel rotatably mounted thereon. A bracket 15 is mounted on the top of the wheel base and has a portion 16 extending upwardly and forwardly from the wheel base. Said extending portion has a rectangular opening 17 running lengthwise thereof at. the bottom of which is formed dove tail guide surfaces 18. A slide member 19 having a dove tail portion 20 in engagement with the dove tail guides 18 is suspended from bracket 15. A diamond holder has a flanged portion 26 with a tapered peripheral surface engaging a correspondingly tapered surface in 'a member 27 attached to the underside of slide 19. These tapered surfaces are circular since member 26 must rotate in member 27. An elongated housing has a portion 31 adapted to fit within opening 17 and attached to dove tail portion 20 of slide 19.

A duct 21 in slide member 19 conducts lubricant from any suitable source through ducts 22 to the under surface of member 15 and through ducts 23 to the dove-tail surfaces 18. Lubricant is also directed to the upper surface of flange member 26 from which it is distributed through grooves 24 and 28 to the tapered surface of flange bearing member 27.

Vertical shaft 32 is rotatably mounted in said housing in bearings 33 and 34. The lower portion of said shaft has a coupling member 35 which fits a slotted portion 36 of diamond holder 25. The upper portion of housing 30 has a pair of parallel cylinders 40 and 41 in which are slidably mounted a pair of double head pistons 42 and 43. Connecting portions 44 and 45 between the heads of pistons 42 and 43 respectively have rack teeth 46 and 47 which engage a pinion 48 on shaft 32. This arrangement provides a balance of the lateral force exerted on shaft 32 by each piston. A reversing dog 50 is mounted on the upper end of shaft 32 in position to actuate a reversing switch 51. The extent of movement of pistons 42 and 43 may be adjusted by means of screws 52 and 53.

Attached to the front end of bracket 15 is a feed mechanism which consists of a feed screw in a resiliently divided nut 61 in a bore 62 in slide'19. Said shaft is rotatably mounted in bearings 63 and 64. A, ratchet wheel 65 is keyed to the extended portion of feed screw 60. A pair of parallel feed pistons 66 and 67 hav; ing pawls 68 and 69 for engaging the ratchet teeth 70 are slidably mounted in cylinders 72 and 73 in said housing 74. A feed of this type is shown in Patent 2,192,308 which was granted March 5, 1940. I

As shown in Figure 1, a profile member having an inwardly tapered surface 81 is mounted on the underside of flange 26. A bell crank 82 having a shoe 83 on one end thereof in engagement with said tapered profile surface is pivoted at 84 on diamond holder 25. The other end of said bell crank 82 has a trueing diamond 85 mounted therein. A leaf spring 86 on the underside of diamond holder 25 engages bell crank 82 at a point between pivot 84 and diamond 85 so as to hold shoe 83 against profile surface 81. The tapered profile surface permits the shape of bell crank 82 to be relatively simple. The taper is in line with the pivot point 84 and thus the rocking action of shoe 83 thereon is uniform in both directions. This reduces the possibility of error in trueing a wheel.

Operation Operation of the trueing device is started by closing of switch 90 which completes a circuit through normally closed limit switch 51 to energize CR1. Contact 1 of CR1 provides a holding circuit for CR1. Contact 2 of CR1 completes a circuit to solenoid which shifts reversing valve 96 to the left against spring 97. Fluid under pressure from pump 100 is directed to said revet-sing valve through line 101. In the left position of said valve as it appears in Figure 4, said fluid is directed through line 102 to the right hand end of cylinder 41, and the left hand end of cylinder 40 causing piston 43 to move to the left and piston 42 to move to the right to rotate shaft 32. When said shaft is rotated in this manner, the lateral load on the bearings is not concentrated in one direction.

Rotation of shaft 32 causes diamond 85 to pass across the surface of wheel 11 in a curved path determined by the shape of profile member 80. When said shaft has rotated the distance in one direction, dog 50 engages limit switch S1 to open the circuit to CR1, thus de-energizing solenoid 95 and permitting spring 97 to shift reversing valve 96 to the right. In this position fluid from line 101 is directed through line to the left end of cylinder 41 and the right end of cylinder 40. At the same time fluid is directed from line 110 through throttle valve to the left end of cylinders 72 and 73. Fluid under pressure to cylinder 73 for resetting piston 67 also acts in cylinder '72 and causes aworking stroke of piston 66 to rotate feed screw 60 and thus feed diamond 85 toward the grinding wheel 11. Diamond rotating piston 43 is moved to the right and piston 42 is moved to the left to rotate diamond holder 25 in a clockwise direction-so that diamond '85 may make a return pass across grinding wheel 11. Dog 50 releases limit switch '51 during this pass to partially close the circuit to CR1 in -readiness for the next dressing operation. When the diamond corn-v pletes its movement in a clockwise-direction, it is stopped by the'engagement of piston 43 with stop screw 53 and remains in this position until solenoid 95 is energized for the next dressing operation.

'I claim:

1. In a grinding machine, a grinding wheel support, a grinding wheel mounted thereon, a radial profile trueing'device for trueing said grinding wheel, a housing, a shaft mounted therein for rotation about an axis substantially tangent to the grinding wheel at a point other than the point of contact between the grinding wheel and work, a diamond holder pivotally mounted on said shaft for movement toward and from said grinding wheel, a profile member having a profile surface in the form of a frustum of acone, the angle of said surface being such that an element of said surface passes through the pivot axis of said diamond holder, and means for holding said diamond holder in engagement with said profile surface.

2. In a grinding machine, a grinding wheel support, a grinding wheel rotatably mounted thereon, a radial profile trueing device mounted for engagement with said grinding wheel at a point other than the point of contact between said wheel and the work piece comprising a housing, a shaft rotatably mounted in said housing, a trueing tool on said shaft and means for rotating said shaft comprising parallel pistons, one on each side of said shaft and movable in a path at right angles to the 2,782,778 r i K A A axis of said shaft, and connections between said pistons and said shaft including a pinion on said shaft, rack teeth on said pistons for engaging-said pinion, whereby to pro vide a balanced driving force acting on said shaft.

3. In a grinding machine, a grinding wheel support, a grinding wheel rotatably mounted thereon, a radial trueing device mounted for engagement with said grinding wheel comprising a housing, a slide member in said housing, a shaftrotatably mounted in said slide, a trueing tool rotated with said shaft and means for rotating said shaft comprising parallel pistons, one on each side of said shaft and movable in a path at right angles to the axis of said shaft whereby to apply driving forces acting simultaneously in opposite directions to provide a balanced rotative force to-rotate said shaft, and a flexible coupling between said tool and said shaft.

4. In 'a grinding machine, a grinding wheel support, a grinding wheel rotatably mounted thereon, a radial trueing device mounted for engagement with said grinding wheel comprising a housing, a slide member in said housing, a shaft rotatably mounted in said slide, a trueing tool on said shaft and means for rotating said shaft comprising parallel-pistons, one on each side of said-shaft and movable with said slide at right angles to the axis of said shaft, connections between said pistons and said shaft for rotating said shaft, and means for directing fluid to actuate said pistons simultaneously in opposite directions.

References Cited in the file of this patent UNITED STATES PATENTS 2,192,308 Greiner Mar. 5, 19.40 2,288,153 Bullock June 30, 1942 2,311,262 Stewart June 30, 1943 2,665,681 Haas Jan. 12, 1954 

